AIRCRAFT pilots know better than anyone else the real scale of the vast Australian Outback.

Three Coffs Harbour pilots are setting off this month to raise money for a service that does more than most to conquer the tyranny of those distances, the Royal Flying Doctor Service.

The 2015 Steadfast Foundation Outback Air Race starts in Esperance in Western Australia on August 23 and finishes on September 4 on Hamilton Island after stopovers in Alice Springs, Birdsville, Winton, Karumba and Cooktown.

Among the 30 teams will be Triple Whiskey on the Rocks, aka businessmen Warren Miller, Geoff Leaver and John Harris, flying VH-WWW, their red and white French-built Tobago TB2 Socata aircraft.

Held once every three years, the event's challenges reflect those faced by the RFDS pilots.

Resembling a time trial rather than a race, the winner of the Outback Air Race comes from piloting skill rather than speed, with teams scored on the ability to predict the time taken to fly between legs.